Higher Fines—Fewer Traffic Offences? A Multi-Site Observational Study

Assess the impact of a 100-per cent increase of fines on compliance with speed-limits (50 km/h) and parking regulations in urban areas. Norm violations were measured through standardized observations in all five major cities in Switzerland before and after fines had been raised by 100 % or more at two pre- and two post-intervention periods. The speed of 20,000 cars was measured, and 10,000 parked cars were controlled. Levels of police controls remained stable over the entire period, but enforcement activity varied considerably across cities. Violations of parking regulations decreased by 32 %. Speed-limit violations remained unaffected in the longer run by higher fines. When cities without relevant enforcement activity were excluded, a reduction by 17 % was observed. No causal inferences can be drawn given the absence of a control area. However, the data suggest that higher fines deter traffic violations, provided enforcement activity remains at relevant levels.